Solar panel efficency
in [Design]
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From: Robert Baer on 1 Jun 2010 00:02 Tim Wescott wrote: > On 05/30/2010 10:29 PM, Michael wrote: >> On May 30, 9:03 pm, Robert Baer<robertb...(a)localnet.com> wrote: >>> Tim Wescott wrote: >>>> On 05/30/2010 03:16 PM, Spehro Pefhany wrote: >>>>> On Sun, 30 May 2010 14:20:26 -0700, the renowned Robert Baer >>>>> <robertb...(a)localnet.com> wrote: >>> >>>>>> I did a survey and this is the best i got. >>>>>> Makers: (1) BP Solar technology: Advanced multicrystalline& >>>>>> monocrystalline silicon nitride; (2) First Solar modules: Thin film >>>>>> cadmium telluride; (3) Nanosolar: Thin film CIGS (copper indium >>>>>> gallium >>>>>> selenium); (4) Sharp: Monocrystalline& polycrystalline >>>>>> (silicon?) (Thin >>>>>> film?); (5) Evergreen Solar: Silicon (Mono? Poly? not mentioned). >>> >>>>>> The questions in above are due to incompleteness of disclosure >>>>>> (on >>>>>> the web). >>> >>>>>> Of those technologies, which one is the MOST efficient in >>>>>> conversion >>>>>> of light / solar energy to electrical power (assume ideal load for >>>>>> given >>>>>> panel)? >>>>>> Is there another (commercially available) technology even more >>>>>> efficient? >>> >>>>> Oh, something like multijunction single-crystal GaAs or InS probably, >>>>> but unless you've got a NASA level budget you probably can't afford >>>>> them. >>> >>>>> The usual efficiency criteria for ground-based applications is $/peak >>>>> watt. >>> >>>> And I _still_ think that the criteria should be the net energy return >>>> over the whole lifetime of the product -- mean _after_ you take into >>>> consideration the entire extract/manufacture/install/dispose cycle of >>>> the panel into account, _including_ the trees you'll need to chop down >>>> to make room for them and some projections of the proportion of panels >>>> that will be retired early due to defects, obsolescence, vandalism, >>>> remodeling, and just plain accident. >>> >>>> Because I think that in principal the whole idea of renewable energy is >>>> a Really Good Thing, but it seems to be in the hands of a bunch of >>>> poly-anna ditzle-brains who turn off all thought processes when >>>> confronted by anything "green", and who are opposed by a bunch of >>>> mean-spirited ditzle-brains who let their thought processes get turned >>>> off by bibles long ago. >>> >>> Well, absolutely NO energy source is renewable; the sun is in a >>> downward nuclear fission / fusion path leading to iron. >>> What i looked for was an energy source that did not require energy >>> rich carbon sources (trees, oil); the other alternative would be foot >>> powered generators. >> >> >> I've always been fond of the SEGS family of concentrating solar >> arrays, 30 to 80 MW each, in the California Mojave Desert. They focus >> sunlight onto a hydrocarbon heat transfer fluid, heating it to between >> 300 and 400 C, which then boils steam for a steam turbine. Apparently >> they can do it for a lower capital cost than the equivalent amount of >> solar cells would cost. >> >> Is this for a third-world project? 100W, huh? No cost constraints? >> Remember, the most efficient technology won't come cheap. What's >> wrong with charcoal? Trees are plenty cheap. > > Somewhere in my brother's extensive collection of railroading books is a > picture of a valley in the American southwest that's been almost > entirely stripped bare of trees, for wood to run the railroad that > served the local mine. > > And there are plenty if citations that I've heard of places in 3rd world > countries where they've stripped their forests bare just for charcoal > for heating and cooking. > > Trees are only cheap for a very little while, then they are very dear > indeed. > Abs-so-tutely!
From: Robert Baer on 1 Jun 2010 00:06 Tim Wescott wrote: > On 05/31/2010 08:38 AM, Jim Thompson wrote: >> On Sun, 30 May 2010 17:21:25 -0700, Tim Wescott<tim(a)seemywebsite.now> >> wrote: >> >>> On 05/30/2010 03:16 PM, Spehro Pefhany wrote: >> [snip] >>>> >>>> The usual efficiency criteria for ground-based applications is $/peak >>>> watt. >>> >>> And I _still_ think that the criteria should be the net energy return >>> over the whole lifetime of the product -- mean _after_ you take into >>> consideration the entire extract/manufacture/install/dispose cycle of >>> the panel into account, _including_ the trees you'll need to chop down >>> to make room for them and some projections of the proportion of panels >>> that will be retired early due to defects, obsolescence, vandalism, >>> remodeling, and just plain accident. >>> >>> Because I think that in principal the whole idea of renewable energy is >>> a Really Good Thing, but it seems to be in the hands of a bunch of >>> poly-anna ditzle-brains who turn off all thought processes when >>> confronted by anything "green", and who are opposed by a bunch of >>> mean-spirited ditzle-brains who let their thought processes get turned >>> off by bibles long ago. >> >> Huh? I think most opposition to "green" energy solutions lies in only >> two camps... >> >> (1) NIMBY's >> >> (2) Those of us who want green, but not at the cost of immediate >> turn-off of existing energy sources... Obamanation-style :-( > > Well, I don't _know_ that green energy is a net positive enterprise or > not. But I've been an engineer for long enough that I've seen entire > herds of non-technical types go thundering after technologies that can't > do anything but cost more than they return. Quite frankly, this whole > green energy thing is showing a lot of the same hallmarks. > > My fear is that the true cost accounting just isn't being done, or is > being done exceptionally belatedly (take biofuel, for instance). It > seems that any time you start talking about "green energy" half the > world gets all googley-eyed and starts talking about how it's going to > Save the World, and the other half starts talking about how it's an > Excuse to Abrogate our God Given Rights. > > And any time people start talking in all caps I get suspicious that > they've stopped thinking. > > It'd be a shame if we put all our resources into "green energy" and find > out that it's really blacker than oil. > I do not care about "green" in this case, just a method to reasonably supply some power to run each school. A foot powered generator is another possible solution.
From: Michael A. Terrell on 1 Jun 2010 00:29 Robert Baer wrote: > > Tim Wescott wrote: > > On 05/31/2010 08:38 AM, Jim Thompson wrote: > >> On Sun, 30 May 2010 17:21:25 -0700, Tim Wescott<tim(a)seemywebsite.now> > >> wrote: > >> > >>> On 05/30/2010 03:16 PM, Spehro Pefhany wrote: > >> [snip] > >>>> > >>>> The usual efficiency criteria for ground-based applications is $/peak > >>>> watt. > >>> > >>> And I _still_ think that the criteria should be the net energy return > >>> over the whole lifetime of the product -- mean _after_ you take into > >>> consideration the entire extract/manufacture/install/dispose cycle of > >>> the panel into account, _including_ the trees you'll need to chop down > >>> to make room for them and some projections of the proportion of panels > >>> that will be retired early due to defects, obsolescence, vandalism, > >>> remodeling, and just plain accident. > >>> > >>> Because I think that in principal the whole idea of renewable energy is > >>> a Really Good Thing, but it seems to be in the hands of a bunch of > >>> poly-anna ditzle-brains who turn off all thought processes when > >>> confronted by anything "green", and who are opposed by a bunch of > >>> mean-spirited ditzle-brains who let their thought processes get turned > >>> off by bibles long ago. > >> > >> Huh? I think most opposition to "green" energy solutions lies in only > >> two camps... > >> > >> (1) NIMBY's > >> > >> (2) Those of us who want green, but not at the cost of immediate > >> turn-off of existing energy sources... Obamanation-style :-( > > > > Well, I don't _know_ that green energy is a net positive enterprise or > > not. But I've been an engineer for long enough that I've seen entire > > herds of non-technical types go thundering after technologies that can't > > do anything but cost more than they return. Quite frankly, this whole > > green energy thing is showing a lot of the same hallmarks. > > > > My fear is that the true cost accounting just isn't being done, or is > > being done exceptionally belatedly (take biofuel, for instance). It > > seems that any time you start talking about "green energy" half the > > world gets all googley-eyed and starts talking about how it's going to > > Save the World, and the other half starts talking about how it's an > > Excuse to Abrogate our God Given Rights. > > > > And any time people start talking in all caps I get suspicious that > > they've stopped thinking. > > > > It'd be a shame if we put all our resources into "green energy" and find > > out that it's really blacker than oil. > > > I do not care about "green" in this case, just a method to reasonably > supply some power to run each school. > A foot powered generator is another possible solution. Replace Gym class and detention with kids running in giant hamster wheels. They will be too winded to use their cell phone in class, and too tired to cause trouble on the way home from school. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
From: Martin Brown on 1 Jun 2010 04:15 On 31/05/2010 23:08, Don Lancaster wrote: > On 5/30/2010 2:20 PM, Robert Baer wrote: >> I did a survey and this is the best i got. >> Makers: (1) BP Solar technology: Advanced multicrystalline & >> monocrystalline silicon nitride; (2) First Solar modules: Thin film >> cadmium telluride; (3) Nanosolar: Thin film CIGS (copper indium gallium >> selenium); (4) Sharp: Monocrystalline & polycrystalline (silicon?) (Thin >> film?); (5) Evergreen Solar: Silicon (Mono? Poly? not mentioned). >> >> The questions in above are due to incompleteness of disclosure (on the >> web). >> >> Of those technologies, which one is the MOST efficient in conversion of >> light / solar energy to electrical power (assume ideal load for given >> panel)? >> Is there another (commercially available) technology even more efficient? > > > There is NO known pv solar panel technology that is capable of net energy. You are *WRONG* this is is a myth. They are not cost effective, but they have net energy gain provided that the units survive for their nominal lifetime. In northern Europe net gain is 4x in sunnier climes around 7x. See for example McKays book without the hot air p41. http://www.inference.phy.cam.ac.uk/withouthotair/c6/page_41.shtml Hot water solar thermal is a lot more cost effective. > > All efficiencies are thus NEGATIVE. No they are not. > > The belief that pv technology today is in any manner renewable, > sustainable, or green is an outright lie, > > Whithout exctption, ALL remain gasoline destroying net energy sinks. Wrong.See Richards & Watt (2007) http://www.inference.phy.cam.ac.uk/sustainable/refs/solar/Myth.pdf > > See http://www.tinaja.com/glib/pvlect2.pdf for a detailed analysis Your "analysis" is just repeated statements unsupported by any calculation of the energy budget to refine and make the doped semiconductor and its frame or energy produced over its lifetime. I think the German subsidies and for that matter the UK ones for PV installation are completely insane on economic grounds. But in more southerly climes where peak sun corresponds with a peak demand for aircon it could make more sense to have PV arrays deployed. And in answer to the ill posed clueless OP question for maximum efficiency research grade PV cells (with cost no object) the best ones in production at present are at about 20%. see eg. http://www.inference.phy.cam.ac.uk/withouthotair/c6/page_47.shtml W/kg or W/$ are usually better measures of performance depending on the application. Regards, Martin Brown
From: Frithiof Andreas Jensen on 1 Jun 2010 07:45
Don Lancaster wrote: > >> Well, I don't _know_ that green energy is a net positive enterprise or >> not. > > > I do. > > It misses by a country mile and clearly remains a gasoline destroying > net energy sink. > > http://www.tinaja.com/glib/nrglect2.pdf > True - but it is a pretty neat vehicle for transferring vast sums from taxpayer to oligarch; what government Is All About, these sad times .... |